The four-time league MVP told Sports Illustrated on Friday that he is returning to the Cleveland Cavaliers.

"My relationship with Northeast Ohio is bigger than basketball," James told SI.com. "I didn't realise that four years ago. I do now."

For James, it marks a complete turnaround from his original free-agent decision in 2010, when he bolted Cleveland for the Miami Heat, creating a 'Big Three' with Dwyane Wade and Chris Bosh that went on to win two NBA titles in their four years together.

"The hardest thing to leave is what I built with those guys," James said. "I've talked to some of them and will talk to others. Nothing will ever change what we accomplished."

The Heat were in the mix for James again this time around. Team president Pat Riley travelled to Las Vegas to meet James on Wednesday in an attempt to lure him back to Miami after the All-Star opted out of his contract following the team's NBA Finals loss to the San Antonio Spurs.

But James said no to Riley and the Heat, instead choosing a Cleveland team that picked him No.1 overall in the 2003 draft out of St. Vincent-St. Mary, where he starred as a high-school player in his native Akron, Ohio.

"Before anyone ever cared where I would play basketball, I was a kid from Northeast Ohio. It's where I walked," James said. "It's where I ran. It's where I cried. It's where I bled. It holds a special place in my heart. People there have seen me grow up. I sometimes feel like I'm their son. Their passion can be overwhelming. But it drives me. I want to give them hope when I can. I want to inspire them when I can."

"I'm not having a press conference or a party," James added. "After this, it's time to get to work."

James, Bosh and Wade all exercised options in their contracts to become free agents this summer, but the thinking was that they would re-do their deals to give the team financial flexibility in an effort to make upgrades to the roster.

Now, the future is uncertain in Miami. Bosh is weighing a maximum-contract offer from the Houston Rockets, which he was leaning toward taking in the event of James' departure, sources told ESPN. Wade also remains a free agent, and the Heat currently have just four players who will be under guaranteed contract for next season.

James spent seven seasons with the Cavaliers, averaging 27.8 points, 7.2 rebounds and 6.9 assists and leading them in 2007 to the NBA Finals, where they lost to the Spurs. The goal for him now will be to get there again with a Cleveland team that boasts All-Star point guard Kyrie Irving and former Kansas star Andrew Wiggins, the No.1 pick in last month's NBA draft.

James said he knows how hard it is to win a championship and that he is "realistic" about the team's hopes next season - but also optimistic.

"My patience will get tested. I know that," James said. "I'm going into a situation with a young team and a new coach. I will be the old head. But I get a thrill out of bringing a group together and helping them reach a place they didn't know they could go. I see myself as a mentor now and I'm excited to lead some of these talented young guys."